CICERO’S APPEAL TO NATURAL LAW IN PHILIPPICS 10 AND 11

Abstract This article uses Cicero’s De legibus to unlock the force of the legal arguments in Philippics 10 and 11, which justify Brutus and Cassius’ respective invasions of Macedonia and Syria by emphasizing their conformity with the ‘law of nature’. Cicero’s rhetorical challenge (1) was to persuade senatorial moderates that giving commands to the conspirators was less threatening to the Republican legal system than were Antony’s arrangements for those provinces. Drawing on his De legibus (2), which identifies a link between positive law and nature based on its capacity to distinguish justice from injustice, Cicero provides this response to his opponents’ charge that Brutus and Cassius have broken the law: (3) because of their virtue, the pair have been able to follow natural law, as Antony has destroyed the force of public law in Macedonia and Syria, but the Senate now has a chance to rebuild the positive legal order, legitimized through its connection to Brutus and Cassius’ actions.